Deuteronomy 25:5-6

Rotherham(i) 5 When brethren dwell together, and one of them dieth, having, no son, the wife of the dead shall not marry outside, to a stranger,––her husband’s brother, shall go in unto her, and take her unto him to wife, and do for her as a husband’s brother. 6 And it shall be, that, the firstborn which she beareth, shall succeed in the name of his brother, who is dead,––so shall his name not be wiped out from Israel.